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Full-Text Articles in Physical Sciences and Mathematics

Seasonal And Spatial Variations In Chemical Composition And Fluxes Of Dissolved Organic Matter And Nutrients In The Lower Milwaukee River, Tarek A. Teber Aug 2016

Seasonal And Spatial Variations In Chemical Composition And Fluxes Of Dissolved Organic Matter And Nutrients In The Lower Milwaukee River, Tarek A. Teber

Theses and Dissertations

Physical, chemical and biological processes directly influence the transport, composition, and fluxes of dissolved organic matter (DOM) in river watersheds. Changes in the abundance and composition of DOM and nutrients (P&N) in the watershed should reflect changes in hydrological cycle, effluent discharge, land-use and land-cover, and anthropogenic activities in the river basin, especially in rivers that run through metropolitan areas such as the Milwaukee River. Despite the importance of DOM to ecosystem health and function, a literature search to date finds no comprehensive accounting of DOM in the Milwaukee River. To examine DOM dynamics, monthly water samples were collected between …


The Function Of Renalase, Brett Allen Beaupre Aug 2016

The Function Of Renalase, Brett Allen Beaupre

Theses and Dissertations

Renalase was originally reported to be an enzyme secreted into the blood by the kidney to lower blood pressure and slow heart rate. Despite multiple reports claiming to confirm this activity in vivo there has been considerable discord in regards to the reaction catalyzed by renalase. The structural topology of renalase resembles that of known flavoprotein oxidases, monooxygenases and demethylases, but the conserved active site residues are unique to renalase. It has been reported that the catalytic function of renalase is to oxidize circulating catecholamines, however in vitro studies have failed to demonstrate a catalytic activity in the presence of …


Iron Uptake And Accumulation Is A Target Of Nickel Toxicity During The Lag Phase In Escherichia Coli, Geoffrey Tuttle Ford Jun 2016

Iron Uptake And Accumulation Is A Target Of Nickel Toxicity During The Lag Phase In Escherichia Coli, Geoffrey Tuttle Ford

Theses and Dissertations

Various transition metals are essential to all forms of life, and are only required in trace amounts. But this dependence comes as a double-edged sword. All organisms must maintain a careful intracellular quota that does not traverse outside an acceptable range. One transition metal in particular is nickel. The importance of this transition metal has been debated widely and its function varies greatly between organisms, including bacteria. However, the adverse effects caused by over exposure to this metal have been the center of much experimentation in recent years. Still, the mechanisms of nickel toxicity and the subsequent effects on cellular …


Structural And Functional Studies Of Nicotinamide Adenine Dinucleotide And Streptolysin S Biosynthesis Proteins From Streptococcus Pyogenes, William T. Booth Jun 2016

Structural And Functional Studies Of Nicotinamide Adenine Dinucleotide And Streptolysin S Biosynthesis Proteins From Streptococcus Pyogenes, William T. Booth

Theses and Dissertations

Invasive infections caused by Streptococcus pyogenes, also known as Group A Strep (GAS), results in approximately 600,000 deaths annually. With evidence of antibiotic-resistant strains of this bacterium on the rise, there is a need for the identification of new drug targets to control these infections. In our approach we target the quinolinate-salvage pathway (QSP) and the streptolysin S (SLS) biosynthesis pathway. The QSP provides a secondary pathway for NAD+ biosynthesis within this organism; the SLS pathway leads to the formation of a quorum sensing molecule (SLS). We hypothesize that inhibition of the pathways will lead to GAS cell death or …


Ligand-Induced Magnetic Changes In Metal Thin Films, Fiona Senta Oberbeck-Oxsher Jun 2016

Ligand-Induced Magnetic Changes In Metal Thin Films, Fiona Senta Oberbeck-Oxsher

Theses and Dissertations

The investigation of magnetic properties of thin films whose surfaces were modified by organic molecules shows that the addition of any functional group to the surface measurably changes the magnetic properties. The effect often scales with ligand strength and is not limited to surfaces with ferromagnetic properties. Improving upon the technique developed by Knaus et al. [1], a stable and sensitive device was developed to measure this magnetic effect using the planar Hall effect (PHE) in order to shed light onto controversial questions of purported paramagnetism of thiolated gold. There is a measureable non-diamagnetic response of thin gold layers when …


The Development Of A High Resolution Deep-Uv Spatial Heterodyne Raman Spectrometer, Nirmal Lamsal Jun 2016

The Development Of A High Resolution Deep-Uv Spatial Heterodyne Raman Spectrometer, Nirmal Lamsal

Theses and Dissertations

Raman spectroscopy is a light scattering technique that has a huge potential for standoff measurements in applications such as planetary exploration because a Raman spectrum provides a unique molecular fingerprint that can be used for unambiguous identification of target molecules. For this reason, NASA has selected a Raman spectrometer as one of the major instruments for its new Mars lander mission, Mars 2020, in the search for biomarkers that would be the indicators of past or present life. Raman scattering is strongest at UV wavelengths because of the inherent increase in the Raman cross section at shorter wavelengths and because …


Interactions Of The Naphthalene Radical Cation With Polar And Unsaturated Molecules In The Gas Phase, Sean P. Platt Jan 2016

Interactions Of The Naphthalene Radical Cation With Polar And Unsaturated Molecules In The Gas Phase, Sean P. Platt

Theses and Dissertations

Characterizing the interactions of solvent molecules with ions is fundamental in understanding the thermodynamics of solution chemistry. These interactions are difficult to observe directly in solution because the number of solvent molecules far exceed that of ions. This lend the gas phase to be the ideal medium in the study ion-solvent interactions on a molecular level. Ionized polycyclic aromatic hydrocarbon (PAH) molecules can readily form hydrogen bonds with neutral solvent molecules in aqueous and interstellar medium. Previous research has been done for stepwise solvation of small molecules such as benzene+, pyridine, and phenylacetylene. The similarity in these results …